In the field of POCT (Point Of Care Testing), analysis chips using SPR (hereinafter referred to as analysis chips) have been actively developed.
Such analysis chips (sensing members or sensor chips) are often formed only from a prism with a metal film (dielectric medium) and a member defining a channel. Sensing members are typically placed in an analysis apparatus that includes a light source and a detector, and the sensing members themselves seldom include a part or member for retaining test reagent (test reagent retention member). In such configurations, a test reagent retention member is often previously incorporated in an analysis apparatus or is separately placed in an analysis apparatus by a user, and a sensing member is placed therein. Since the test reagent retention member and the sensing member are individually handled in this way, preparation for a measurement and cleaning up thereof are likely to be complicated.
In POCT, test reagent retention members and sensing members are often used once and thrown away in terms of work efficiency and safety. Such a process requires a complicated user work since a test reagent retention member and a sensing member are individually disposed. Furthermore, in a test of detecting a biological substance such as protein or DNA, there is a biohazard risk for the user.
In recent years, there has been an increasing need for a chip in which a test reagent retention member is integrated with a sensing member in terms of improving the usability (ease of use) and achieving unified lot management of test reagent retention members and sensing members (management of products with respect to each product unit) which can improve the detection precision by maintaining the relation between the test reagent and the sensing.
Patent Document 1 discloses an example of such integration, in which a plate main body as a test reagent retention member is integrated with a detection chip as a sensing member.
In particular, the technique proposed in Patent Document 1 is such that a detection groove 13 with a V-shaped cross section is formed in the detection chip 11, and an electric field enhancing layer 14 is formed on the surface thereof. With this configuration, surface plasmon is likely to be readily excited (see paragraphs 0044 to 0045, FIG. 7 (b), Example 1 and Example 2).